Apparatus for automatically filling well conduits with fluid



J. F. MUSE Feb. 24, 1959 APPARATUSFQR AUTOMATICALLY FILLING WELLCONDUITS WITH FLUID Filed April 27. 1953 2 Sheets-Sheet 1 5 5 mm m M w1% W J YM B E. w r f L L I L, L VIZ f w 2 A y 0 J. F. MUSE Feb. 24, 1959APPARATUS FOR AUTOMATICALLY FILLING WELL COND UITS WITH FLUID FiledApril 27, 1955 2 Sheets-Sheet 2 FEE-5 INVENTOR. JOA A /T M05! zgsnnss5-: APPARATUS F ORAUTOMATICALLY FILLING WELL. :CONDUITS .WITH. FLUIDJohn FQMuse, Montebello, Calif assignor to Baker Oil 5 Tols',*Inc;,Vernon, "Calif-3 a corporation of California Application April 27, 1953,Serial No. 351,396

i 20 Claims.{ (Cl. 166-225) The present invention relatesi tosubsurfacewell appa- .:ratus, and more particularly to' apparatus for controllably..fill ing a conduit'string, such as well casing or drill pipe, withfluid .as the string isbeing lowered in a well bore.

. Anaobject .of the present invention is to provide im- ...provedapparatus for automatically controlling the rate .atwhich fluid in thewell bore can flow into .the conduit string in which the apparatus isembodied.

A further object of the invention is to provide apparatus .whichautomatically reduces flow of fluid inv the conduit stringdisposed inthe well bore when the velocity of flow therein tendsv to increase, andwhich increases the flow tof fluid as its velocity tends to decrease. Ina more limited .sense, the apparatus provides a substantially constant:.flow .of fluid inithe conduit string.

. .Another object of theinventionis to provide an apparatusv adapted tobeincorporated in a conduit stringtoabe :disposed in a well bore, inwhichtheapparatus embodies a backpressure valve to prevent upward flowof fluid'in the conduit string, but in which provision is made to allowthe conduit string to fill with fluid at a controlled rate as ituislowered .in the; well bore, "the back pressure valve being operable toperform its function at all times.

.1. This .inventionpossesses many; other" advantages, and

- ..has.other objects which maybezmademore clearly apparent.fromaconsideration of a form in' which it may-:be

embodied- .This form is-showrr-in thev drawings accom- .willnow.bedescribed intdetail", fopthepurposeofillustratingzthegeneral.principles.ofithe invention; but it is tobeunderstood that such detailed description is: not to :be taken inalimitingsense, since .thescope of theinvention isebest defined by theappended. claims.

l" Referring to the drawings: I Fig; 1. is .a. longitudinal section.throughan apparatus embodying the invention,.disposed.in'awell bore andwith .the valve mechanism in openposition;

. Fig. 2 is an enlarged. fragmentary sectionzof part-of theapparatus-disclosed in .Fig; l;

Fig. 3. is a: side elevational view of a locking member incorporated inthe apparatus;

- Fig. 4 is a .view similar to .Fig.,1, disclosing ,parts of .theapparatusinanother relative position; v

' Fig. 5. is aview similar to Fig. l,-disc losing.thei appa .ratus withcertainparts in still another relative position. .As. disclosed in thedrawings,..tl1eapparatus A; is embodiedin a stringoi casing Bzdisposedin awell boreC, the. apparatus being specifically. provided'in thecasing ever, that .the apparatus. is also user'ulin other {types .ofconduit. strings, and that it .can. also -.be incorporated atintermediate points in the conduit string.

As specifiically illustratedinthe drawings, theapparatus includes anouter tubular member 10 havingan upper threaded box'"11 threadedlyattached tothe lower. pin12 of an 'adjacent'casing sectiQnLB; the casingsections being .connected to one anotherand extending to the top of. the

*well bore, in'which" the casing'string is to be lowered.

Hpanying; and. forming. part .of'thepresent specification..;. =It

2,874,785 Patented Feb. 24, 1959 wThe tubulargmember- 10 hasa-cementitious, plug 13 cast "Itherein, this plug being; inseparablyunited ,to the tubular member by providing longitudinally; spacedcircumferential grooves 14 in-the .tubularu-member in' whichcementitious material will'flow during thecasting operation to i providethe locking plug ribs 15 -.inuthe grooves. The

lower end 16 of the plug isrounded, to provide a guiding nose forfacilitating passage of the casing stringpast restrictions or otherobstructions.encounteredin thewell bore during descent of the casingstring therewithin.

: An upwardly closing backpressure valve. device 17-. is incorporated in'the apparatus totpr'eclude return flow-of ,fluid .into the casingstring B after it has been lowered to seat 21rand 'into engagement withaplurality of circumferentially spaced lugs or fingers 23 between whichthe fluid can'flow in moving through the casing shoe between its upperand lowerxends.

Inasmuchas it 'is desired to.-have the casing string B .fillautomatically with the'well bore-fluid as it is lowered therewithin, acontrol mechanism-tor. permitting such flow is disposed in'theapparatus:above :the backpresprovided forprecluding ingressof fluid into.the-conduit string above theuback pressure valve mechanism-17,a,in

'order that. all fluid. must .thenbe. moved. dowmthroughdhecasingstring. for, ejectiomthrough vllZS lower end, ,-the .tendency of.such fluidto flowaback intozthe. casingstr ing ,being prevented byengagement of theballvalvezmemher. 22 with,its-.companionaseat 21.

.As..shown; .specificallyr in. the drawings; .the automaticvalvemechanismfor eontrollingthepassage of*fluid into the conduit stringincludes acomposite. housing 24 secured within. the .cemeirtitious plug;.13,.,as .by providing longitulsdinally spaced'peripheral grooves .25on. .the housing, in whichf .the...cementitious. material will... flowduring the casting operation to form lockingrribs lol T his .housing24.includes a. lower housing. section 27:.threaded.into an intermediatehousingsection -28 .having. a ..p1urality.;of

shoe of the casing string. It is to ,be.understood,-. how- .radial.ports. 29in alignment QWithMcOmpanion :.ports,. 30 extendingthrough.the. cementitious plug. 13. and. the. tubular. .member 10. Theintermediate 7 housing... sections28,v is threadedly secured. to. thelowenend. of anupper housing section 31, .which. forms=part;of a ,guideto prevent;-.rotationof a..:sleeve..valve. member .32 that. is-reciprocable within the housing 24.'f'lhis'sleeveavalvesmember iselongate and has. radial ports 33 therethrough; which are maintained.inrthelsame. radial planesxas the.ports,29.,., 30

through, the intermediate housing section 128,. plug liand tubularmember, Ill-by alpin and slot,connection;;As disclosed, such. pirna'ndslot connection includes a lpin 13 4 threaded in a r'adial'directioninto the upperporztionfbf the sleeve valve member 32 and received withina companion longitudinal groove-or slot 35 in the upper housing section31. ,7 I,

When the sleeve ports 33 are aligned with the other ports 29, 30, fluidcanflow between the exterior and interior of the'casing shoe A, thisfluid passing upwardly through a restricted passage or orifice 36 in theupper portion of the sleeve valve member 32 and into the casing sectionB thereabove, for continued upward flowing through the casing string.Leakage of fluid between the housing 24 and valve member 32 is precludedby the provision of an upper elastic seal ring 37 on one'side of thehousing ports 29 engaging the periphery of the sleeve valve 32 above itsports 33. This seal ring may be disposed in a housing groove 38 formedby the upper and intermediate housing sections 31, 28, between which thering 37 is clamped. A similar lower seal ring 39, of

rubber or rubber-like material, is disposed in a groove 40 formedbetween the intermediate housing section 28 and a clamp ring 41 belowthe housing ports 29. This clamp ring 41 is held in position by theupper end of the lower housing section 27.

The ports 33, 29, 30 will be in alignment when a stop and latch ring 42,disposed within a peripheral groove 43 in the sleeve valve 32, engagesan inwardly and downwardly tapering shoulder 44 provided in the lowerhousing section 27. This stop and latch ring 42 is split and is capableof being forced inwardly within the groove 43 and into a position inwhich the periphery of the ring 42 has a diameter no greater than theinside diameter of the lower housing section 27, which will allow theentire sleeve 32 to move downwardly for the purpose of closing the portsthrough the housing 28, plug 13 and tubular member 10, this closingposition being determined by the reception of the split latch ring 42within a lock groove 45 in the housing 24 disposed a substantialdistance below the shoulder 44. When the ring 42 enters this groove 45in the manner described hereinbelow, then the sleeve ports 33 will bedisposed below the lower non-metallic seal ring 39, preventing fluidcommunication between the sleeve ports 33 and the radial ports 29, 30through the housing 28, cement plug 13 and tubular member 10.

As was stated above, the latch ring 42 has, as one of its functions,engagement with the tapered shoulder 44 to locate the sleeve ports 33 inalignment with the radial ports 29, 30. When in this position, the portsare in full communication with each other, allowing unimpeded flow offluid to take place from the exterior of the tubular member 10 to theinterior of the sleeve valve member 32. The sleeve valve 32 is urged ina downward direction toward the position just mentioned by a springmember, which is preferably in the form of a rubber or rubberliketension sleeve 47, the upper end of the sleeve being secured to thelower portion of the sleeve valve member 32 by suitably clamping anenlarged upper end 48 thereof between the sleeve valve member 32 and aretainer ring 49 secured to the sleeve valve 32 in any suitable manner,

as through use of the radial pins 50. The wall of the' housing 24prevents the retainer ring 49 from becoming dissembled from the sleeve32.

In a similar fashion, the lower end 51 of the spring sleeve member 47 isof enlarged cross-section and is clamped between the lower portion ofthe housing section 27 and a retainer member 52 resting upon theupperend of the valve seat 21 and secured to the lower housing sectionby a plurality of radial pins 53. To equalize the fluid pressure on bothsides of the rubber sleeve 47 it may be provided with a plurality ofcircumferentially spaced, longitudinally extending slots 54.

When the ports 33, 29, 30 are in fully aligned and completely openedposition, with the ring 42 engaging the shoulder 44, the rubber springsleeve member 47 may have no tension or slight tension therein. Theupward movement of the sleeve valve member 32 within the housing 24 willstretch the rubber 47 and cause it to tend to move the sleeve valve 32downwardly to its initial position, as shown in Fig. l-in which theports are fully open. The upward movement of the sleeve valve 32 occursunder the action of the fluid flowing through the ports 33, 29, 30 andupwardly through the orifice 36 in the upper portion of the sleevemember. The fact that such fluid is throttled by the orifice passage 36tends to build up a back pressure on the lower portion of the orifice,to move the sleeve valve 32 in an upward direction, thereby misaligningthe sleeve valve ports 33 with respect to the other radial ports 29, 30of the apparatus, andelfecting a throttling of the fluid that can flowbetween the radial ports.

If fluid is flowing at a relatively low rate through the radial ports29, 30, 33, very little back pressure would be built up within thesleeve 32 tending to elevate it. Accordingly, the sleeve valve 32 wouldbe disposed in the fully open position disclosed in Fig. 1. In the eventthe velocity of the fluid passing through the radial ports 29,

30, 33, and upwardly through the orifice 36, increases substantially,then the back pressure built up in the sleeve '32 on the lower side ofthe orifice would elevate the sleeve valve to disalign the ports 33 and29, 30, in the manner disclosed in Fig. 4, reducing the effectivepassage area between the housing ports 29 and the sleeve valve ports 33,and thereby throttling the flow at such points. Ac-

' cordingly, it is evident that as the velocity of flow through theorifice 36 tends to increase, a greater throttling action occurs betweenthe ports 33 and 29, through the longitudinal shifting of the sleevevalve member 32 in the housing 24 against the tension of the rubberspring sleeve 47. This throttling action maintains the volume of fluidpassing through the orifice 36 at a substantially constant rate, sincedecrease in the velocity will cause the rubber spring 47 to pull thesleeve valve 32 back down to a position in which its radial ports 33 aremore fully aligned with the radial ports 29, 30 in the housing 28, plug13 and tubular member 10.

The rate at which fluid will flow into the conduit string B will dependupon the viscosity of the drilling mud, or other fluid in the well bore,the specific gravity of this fluid, the area of the orifice 36, and theforce exerted by the rubber tension sleeve 47. The orifice diameter andthe strength of the spring member or tension sleeve 47 may be selected,in dependence upon the specific gravity and viscosity of the fluid inthe well bore, to insure a relatively slow flow rate of fluid into theconduit string, such that the fluid will not overflow at the top of thehole and drench the surface equipment and personnel.

The fluid will continue flowing into the apparatus during lowering ofthe conduit string B through the fluid in the well bore. When theconduit string or casing has reached the desired depth in the well bore,the fluid level within the casing will rise to approximate equality withthe fluid level around the casing string. Thereafter, fluid may bepumped down the casing string B, the restricted orifice 36 causing aback pressure to build up above the sleeve valve member 32, overcomingthe tension of the split latch ring '42, the tapered shoulder 44 forcingthe latch ring 42 inwardly within the groove 43, whereupon the sleevevalve 32 can be shifted downwardly to the position disclosed in Fig. 5,in which the latch ring 42 will snap into the companion housing groove45, precluding return of the sleeve to its initial position.

When the sleeve 32 is locked in this downward position, its radial jports 33 will be disposed below the lower seal ring 39 in 32 is pumpeddownwardly to the extent required, but the rubber sleeve valve 47 willnot restrictthe flow offlilid downwardly through the apparatus.

Circulating fluid, cement slurry, and the like, may now be pumped downthe casing string B, shifting the ball valve member 22 downwardly fromits seat 21, this fluid flowing around the ball valve member 22 andbetween the stop fingers 23 for discharge from the shoe A and for upwardpassage around the casing string B. When the pumping action is stoppedand the fluid pressure in the casing string relieved, any tendency forfluid to flow back into the shoe A and the conduit string B will beprecluded by the upward movement of the ball valve member 22 intoengagement with its companion seat 21 and seal ring 20.

It is to be noted that the seal rings 37, 39 on opposite sides of thehousing ports 29 slidably engagethe periphcry of the sleeve valve member32, and that the latter member has the same external diameter at suchpoints of slidable engagement. Accordingly, the pressure acting on theexterior of the sleeve valve member 32 is counterbalanced, so that thehydrostatic heads of fluid within and exteriorly of the apparatus do nottend to shift the sleeve valve member in either direction. It is merelythe velocity of the fluid flowing through the orifice 36, and whichbuilds up the back pressure on the underside of the orifice, which iseflective to tend to elevate the sleeve valve 32 against the tension ofthe rubber spring member 47, and which determines the degree ofthrottling action caused by the misalignment of the ports 33 and 29, 30.

Although disclosed specifically in combination with a back pressurevalve member 17, it is evident that the apparatus for controlling theflow of fluid into the conduit string B is eflective in the absence of aback pressure valve mechanism, as, for example, by making the lowerportion of the conduit string imperforate at the location of the backpressure valve apparatus. It is also evident that the apparatus isuseful in general for controlling the flow of fluidintoiconduit strings,as, for example, in its use for production apparatus to automaticallyregulate the flow of well production into a tubing or similar conduitstring positioned in the well bore. I t

The inventor claims: c

i 1. In well apparatus: tubular means adapted to be incorporated in aconduit string to be loweredin a Well bore; a back pressure valve insaid tubular means adapted to close in an upward direction; said tubularmeans having a port through its side Wall above said back pressurevalve; 21 valve member in said tubular means having a passagetherethrough in fluid communication with said back'pressure valve andmovable with respect to said port to regulate the flow of fluidtherethrough, said'valve member having a flow restricting passagethrough which fluid flowing through said port and into said valve memberpasses to build up a back pressure tending to elevate said'valve memberto restrict fluid flow through said port; said valve member beingmovable downwardly to a position closing said port.

2. In well apparatus: tubular means adapted to be incorporated in aconduit string to be lowered in a well bore; a back pressure valve insaid tubular means adapted to close in an'upward direction; said tubularmeans hav-' ing a port through its side Wall, above'said back pressurevalve; a valve member in said tubular means having a passagetherethrough in fluid communication with said back pressure valve andmovable with respect to said port to regulate, the flow of fluidtherethrough, said valve member having a flow restricting passagethrough which fluid flowing through said port and into said valve memberpasses to build up a back pressure tending to elevate said valve memberto restrict fluid flow through said port; said valve member beingmovable downwardly to a position closing said port, andspring meansacting on said incorporated in a conduit string "to be lowered in a wellbore; a back pressure valve in saidtubular means adapted to close in anupward direction; said tubular means having a port through its side wallabove said back pressure valve; a valve member in said tubular meanshaving a passage therethrough in fluid communication with said backpressure valve and movable with respect to said port to regulate theflow of fluid therethrough, said valve member having a, flow restrictingpassage through which fluid flowing through said port and into saidvalve member passes to build up a back pressure tending to elevate saidvalve memberto restrict fluid flow through said port; said valve memberbeing movable downwardly in said tubular means to a position closingsaid port; and means for securing said valve member in said port closingposition.

4. In well apparatus; tubular means adapted to be incorporated in aconduit string to be lowered in a well bore; a back pressure valve insaid tubular means adapted to close in an upwarddirection; said tubularmeans having a port through its side wall above said back pressurevalve; a valve member in said tubular means having a passagetherethrough in fluid communication with said 'back pressure valve andmovable'with respect to said port to regulate the flow of fluidtherethrough, said valve member having a flow restricting passagethrough which fluid flowingthrough said port and into said valve memberpasses to build up aback pressure tending to shift said valve member inone longitudinal direction with respect to said tubular meansto restrictfluid flow through said port; said valve member being movable in theother longitudinal direction to a position closing said, port.

5. Inwell apparatus: tubular means adapted to be incorporated in aconduit string to .be lowered in a well bore; a back pressurevalve insaid tubular means adapted to close in an upward direction; said tubularrneans having a port through its side wallabovesaid back pressure valve;a valve member in said tubular means having a passage therethroughin'fluid communication with said back pressure valve and movable with,respect to said,

port to regulate the flow of fluid'therethrough, said valve memberhaving a flow restricting passage through which fluid flowingthroughsaid port and into said valve member passes to build up a backpressure tending to shift said valve member in one longitudinaldirection with respect to said tubular means to restrict fluid flowthrough said port; said valve member beingmovable longitu-j dinally insaid tubular 'means in the other direction to a position closing saidport;and means for securing said valve member in said port closingposition.

6. In well apparatus: tubular means adapted to be incorporated in aconduit string to be lowered in a well bore; said tubular means having aport through its side wall; a valve member in said tubular means movablewith respect to said port to regulate the .flow of fluid therethrough,said valve member having an axial, central flow restricting passagethrough which fluid flowing through said port and into said valve memberpasses to build up a back pressure tending to movesaid valve member inone longitudinal direction within said tubular means to restrict fluidflow through said port; and means on said valve member for enabling saidvalve member to be shifted in the opposite longitudinal direction to aposition closing said port.

' 7. In well apparatus: tubular means adapted to be build up a backpressure tending to movesaid valve member in one longitudinaldirection'within said tubular means to restrict fluid flow through saidport; means on said valve member for enabling said valve member to beshifted in the opposite'longitudinal direction to a position closingsaid port; and spring means acting on said valve member to urge it to aposition allowing greater flow of fluid through said port.

8. In well apparatus: tubular means adapted to be incorporated in aconduit string to be lowered in a well bore; a back pressure valve insaid tubular means adapted to close in an upward direction; said tubularmeans having a port through its side wall above said back pressurevalve; a sleeve valve member in said tubular means having a passagetherethrough in fluid communication with said back pressure valve andhaving a port adapted to be aligned with respect to said tubular meansport to allow full flow of fluid through said ports, said sleeve valvemember being shiftable to disalign said ports to restrict the flow offluid therethrough, said sleeve valve member having a flow restrictingpassage through which fluid flowing through said ports and into saidsleeve valve member passes to build up a back pressure tending toelevate said sleeve valve member to disalign said ports and restrictfluid flowing therethrough; said valve memher being movable downwardlyto a position closing said port.

9. In well apparatus: tubular means adapted to be incorporated in aconduit string to be lowered in a well bore; a back pressure valve insaid tubular means adapted to close in an upward direction; said tubularmeans having a port through its side wall above said back pressurevalve; a sleeve valve member in said tubular means having a passagetherethrough in fluid communication with said back pressure valve andhaving a port adapted to be aligned with respect to said tubular meansport to allow full flow of fluid through said ports, said sleeve valvemember being shiftable to disalign said ports to restrict the flow offluid therethrough, said sleeve valve member having a flow restrictingpassage through which fluid flowing through said ports and into saidsleeve valve member passes to build up a back pressure tending toelevate said sleeve valve member to disalign said ports and restrictfluid flowing therethrough; releasable stop means in said tubular meansengageable with said sleeve valve member to limit downward movement ofsaid sleeve valve member and fully align said sleeve valve member portwith said tubular means port; and means for releasing said stop means toenable said sleeve valve member to be shifted downwardly to a positionclosing said tubular means port.

10. In well apparatus: tubular means adapted to be incorporated in aconduit string to be lowered in a well bore; said tubular means having aport through its side wall; a sleeve valve member in said tubular meanshaving a port adapted to be aligned with respect to said tubular meansport to allow full flow of fluid through said ports, said sleeve valvemember being shiftable to disalign said ports to restrict the flow offluid therethrough, said sleevevalve member having an axial, centralflow restricting passage through which fluid flowing through said portsand into said sleeve valve member passes to build up a back pressuretending to elevate said sleeve valve member from a position restrictingfluid flow through said port to disalign said ports and restrict fluidflowing therethrough; and means on said sleeve valve member enablingsaid sleeve valve member to be shifted downwardly in said tubular meansto a position closing said port in said tubular means.

11. In well apparatus: tubular means adapted to be incorporated in aconduit string to be lowered in a well bore; said tubular means having aport through its side wall; a sleeve valve member in said tubular meanshaving a port adapted to be aligned with respect to said tubular meansport to allow full flow of fluid through said ports, said sleeve valvemember being shiftable to disalign said ports to restrict the flow offluid therethrough, said sleeve. valve member having a flow resrictingpassage through which fluid flowing through said ports and into saidsleeve valve member passes to build up a back pressure tending toelevate said sleeve valve member to disalign said ports and restrictfluid flowing therethrough; releasable stop means in said tubular meansengageable with said sleeve valve member to limit downward movement ofsaid sleeve valve member and fully align said sleeve valve member portwith said tubular means port; and means for releasing said stop means toshift said sleeve valve member downwardly to a position closing saidtubular means port.

12. In well apparatus: tubular means adapted to be incorporated in aconduit string to be lowered in a well bore; said tubular means having aport through its side wall; a valve member in said tubular means movablewith respect to said port to regulate the flow of fluid therethrough,said valve member having a flow restricting passage through which fluidflowing through said port and into said valve member passes to build upa back pressure tending to move said valve member in one longitudinaldirection within said tubular means to restrict fluid flow through saidport; means on said valve member for enabling said valve member to beshifted in the opposite longitudinal direction to a position closingsaid port; and an elastic sleeve secured to said valve member andtubular means for urging said valve memher from a position restrictingfluid flow through said port to a position fully opening said port.

13. In well apparatus: tubular means adapted to be incorporated in aconduit string to be lowered in a well bore; a back pressure valve insaid tubular means adapted to close in an upward direction; said tubularmeans having a port through its side wall above said back pressurevalve; a shiftable valve member in said tubular means having a passagetherethrough in fluid communication with said back pressure valve, saidvalve member having a port alignable with said port of the tubular meansto permit fluid to flow through said port into said valve member andthen upwardly into said tubular means and the conduit string; means forlocating said valve member in said tubular means with said valve memberport in alignment with said port of said tubular means; means withinsaid valve member and responsive to the pressure of the fluid flowingthrough said ports for regulating the flow of fluid through said ports;and means for shifting said valve member downwardly in said tubularmeans to a position disaligning and closing said ports to prevent flowof fluid therethrough.

14. In well apparatus: tubular means adapted to be incorporated in aconduit string to be lowered in a well bore; a back pressure valve insaid tubular means adapted to close in an upward direction; said tubularmeans having a port through its side wall above said back pressurevalve; a shiftable valve member in said tubular means having a passagetherethrough in fluid communication with said back pressure valve, saidvalve member having a port alignable with said port of the tubular meansto permit fluid to flow through said port into said valve member andthen upwardly into said tubular means and the conduit string; means forlocating said valve member in said tubular means with said valve memberport in alignment with said port of said tubular means; means withinsaid valve member and responsive to the pressure of the fluid flowingthrough said ports for regulating the flow of fluid through said ports;means for shifting said valve member downwardly in said tubular means toa position disaligning and closing said ports to prevent flow of. fluidtherethrough; and means for securing said valve member in said portclosing position.

15. In well apparatus: tubular means adapted to be incorporated in aconduit string to be lowered in a well bore; a back pressure valve insaid tubular means adapted to close in an upward direction; said tubularmeans having a port through its side wall above said back pressurevalve; a shiftable valve member in said tubular means having a passagetherethrough in fluid commu nication with said back pressure valve, saidvalve member having a port alignable with said port of the tubular meansto permit fluid to flow through said port into said valve member andthen upwardly into said tubular means and the conduit string; meanswithin said valve member and responsive to the pressure of the fluidflowing through said ports for regulating the flow of fluid through saidports; releasable means for preventing downward movement of said valvemember to a position disaligning said ports; and means for shifting saidvalve member downwardly in said tubular means to release said releasablemeans and then locate said valve memher in a position disaligning andclosing said ports to prevent flow of fluid therethrough.

16. In well apparatus: tubular means adapted to be incorporated in aconduit string to belowered in a well bore; a back pressure valve insaid tubular means adapted to close in an upward direction; said tubularmeans having a port through its side wall above said back pressurevalve; a shiftable valve member in said tubular means having a passagetherethrough in fluid communication with said back pressure valve, saidvalve member having a port alignable with said port of the tubular meansto permit fluid to flow through said port into said valve member andthen upwardly into said tubular means and the conduit string; meanswithin said valve member and responsive to the pressure of the fluidflowing through said ports for regulating the flow of fluid through saidports; releasable means for preventing downward movement of said valvemember to a position disaligning said ports; means for shifting saidvalve member downwardly in said tubular means to release said releasablemeans and then locate said valve member in a position disaligning andclosing said ports to prevent flow of fluid therethrough; and means forsecuring said valve member in such port closing position.

17. In well apparatus: tubular means adapted to be incorporated in aconduit string to be lowered in a well bore, said tubular means having aport'through its side wall; a shiftable valve member in said tubularmeans having a passage therethrough and also having a port alignablewith said port of the tubular means to permit fluid to flow through saidports into said valve member and then upwardly into said tubular meansand the conduit string; means for locating said valve member in saidtubular means with said valve member port in alignment with said port ofsaid tubular means; means within said valve member and responsive to thepressure of the fluid flowing through said ports for regulating the flowof fluid through said ports; and means for shifting said valve memberdownwardly in said tubular means to a position disaligning and closingsaid ports to prevent flow of fluid therethrough.

18. In Well apparatus: tubular means adapted to be incorporated in aconduit string to be lowered in a well bore, said tubular means having aport through its side wall; a shiftable valve member in said tubularmeans having a passage therethrough and also having a port alignablewith said port of the tubular means to permit fluid to flow through saidports into said valve member and then upwardly into said tubular meansand the conduit string; means for locating said valve member in saidtubular means with said valve member port in alignment With said port ofsaid tubular means; means within said valve member and responsive to thepressure of the fluid flowing through said ports for regulating the flowof fluid through said ports; means for shifting said valve memberdownwardly in said tubular means to a position disaligning and closingsaid ports to prevent flow of fluid therethrough; and means for securingsaid valve member in such port closing position.

19. In well apparatus: tubular means adapted to be incorporated in aconduit string to be lowered in a well bore, said tubular means having aport through its side Wall; a shiftable valve member in said tubularmeans having a passage therethrough and also having a port alignablewith said port of the tubular means to permit fluid to flow through saidports into said valve member and then upwardly into said tubular meansand the conduit string; means within said valve member and responsive tothe pressure of the fluid flowing through said ports for regulating theflow of fluid through said ports; releasable means for preventingdownward movement of said valve member to a position disaligning theports; and means for shifting said valve member downwardly in saidtubular means to release said releasable means and locate said valvemember in a position in which said ports are disaligned and closed toprevent flow of fluid therethrough.

20. In well apparatus: tubular means adapted to be incorporated in aconduit string to be lowered in a well bore, said tubular means having aport through its side wall; a shiftable valve member in said tubularmeans having a passage therethrough and also having a port alignablewith said port of the tubular means to permit fluid to flow through saidports into said valve member and then upwardly into said tubular meansand the conduit string; means within said valve member and responsive tothe pressure of the fluid flowing through said ports for regulating theflow of fluid through said ports; releasable means for preventingdownward movement of said valve member to a position disaligning theports; means for shifting said valve member downwardly in said tubularmeans to release said releasable means and locate said valve member in aposition in which said ports are disaligned and closed to prevent flowof fluid therethrough; and means for securing said valve member in suchport closing position.

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